This would really help a lot. I have been kind of confused about this matter. Under drive pulleys are said to add another 5 to 10 rwhp? If so, I remember someone telling me on this forum that under drive pulleys cancel out the use of A/C or inner car appliances. I have subwoofers and an amp. Would under drive pulleys affect this in anyway on how they sound? Would it make my air conditioning system worse? How does it affect the car besides adding a few extra horses?

 

I have them and with the exception of the added performance there are no issues with these. I have the Shaker 1000. BTW they don't add horsepower they free up horsepower.